Referendum question should be moved to the `subtitle` field.

Using the `ballot` field for referendum questions causes some pretty bad UX, as it wasn't designed for very long text. In the original design, the referendum question was to be plugged into `subtitle` and the UI is adjusted for that.

Proposed changes:
* some shorthand should be used for `ballot`, like "Întrebare 1"/"Întrebare 2" or "Interzicerea OUG despre justiție"
* The full question text should be moved to `subtitle`
* `Validat`/`Invalidat` should be moved to a separate field in `meta` (maybe a boolean or an enum?).
* The page header should be changed to either display both `ballot` and `subtitle` in different font sizes, either only display `subtitle` and hide `ballot` when `subtitle` is present.

Examples of how it looks bad: